The present invention generally relates to monitoring the performance of a resource, which resides in a computer system.
A storage device is one target of performance monitoring. Technology related to monitoring the performance of a storage device using a threshold is known (For example, U.S. Pat. No. 6,032,224 and U.S. Pat. No. 7,120,832).
There is technology for making the one of a plurality of logical volumes, which resides in a storage system, a copy source, making the other of this plurality of logical volumes a copy target, and copying data stored in the copy source volume to the copy target volume. For a copy to be performed, input/output, which is different from input/output to a logical volume in accordance with an I/O command sent from a host computer, is carried out. Thus, a difference in the performance actually capable of being manifested can occur between a resource, which is involved in the copying of data, and a resource, which is not involved in this copying, even though the capabilities of these resources are substantially the same.